Technical Field
The present invention relates to a toner, a toner housing unit, an image forming apparatus and an image forming method using the toner.
Description of the Related Art
Technologies to fix a toner at low energy are desired because environment-oriented products have grown in prosperity in recent years. There are various means therefor, and particularly, a toner for forming an electrostatic latent image, which is fixable at lower temperature is strongly demanded.
As a means for lowering the fixable temperature of a toner, a glass transition temperature (Tg) of the toner binder is typically lowered. However, when the Tg is simply lowered, powders may aggregate (aggregation of a powder is called “blocking” in the present invention) in image forming apparatuses, resulting in inability of operation of the image developer. If not inability of operation thereof, the powder may aggregate in a toner housing unit and the toner cannot be fed and lowers in density, resulting in production of abnormal images.
When many images are continuously produced by a printer, the images may adhere to each other just after produced because they are not cooled enough after heated to fix the images (this is called “ejected paper blocking” in the present disclosure). Therefore, the toner need to have better anti-blocking properties of ejected papers. Further, when Tg is lowered, the toner on the surface of a fixed image has worse preservability. The fixed image which easily melts and transfers adheres to other recording medium when the ejected papers are stored at high temperature with a pressure, they may not be stored for long periods.
Simply lowering Tg can hardly obtain a toner having good image preservability and low-temperature fixability without the “blocking” and “blocking of ejected papers”.